Abstract

This TIP proposes to use Tcl's package configuration database (see TIP #59) to register whether Tk was compiled with support for Xft.

Rationale

As of version 8.5, Tk has optional support for Xft (the modern replacement for server-side fonts in X11). However, at present application code has no way to determine whether or not Xft support was enabled when Tk was built. The package configuration database facility introduced in TIP #59 seems like an ideal place to record this information.

Proposal

If Tk was configured with --enable-xft, the command

tk::pkgconfig get fontsystem

shall return the value xft.

Notes

The change as currently proposed is the minimum necessary to satisfy the requirement listed in the Rationale. In particular: nothing else in Tk currently calls Tcl_RegisterConfig(), so if Xft support is not enabled the tk::pkgconfig command will remain undefined.

This TIP (or something like it) is a prerequisite for a script-level implementation of TIP #145, which will need to distinguish whether or not Xft is in use.